Several reports of the recent Intel HD 530 graphics driver (126.96.36.19990) causing BSOD and periodic crashes.
Rollback to older driver seems to work until Dell and Intel get this resolved.
Thanks for providing this, I experienced similar BSOD's a week ago. I even experienced them just locking and unlocking my display. I will keep an eye on Windows trying to upgrade it automatically. Hopefully Dell will release a fix very soon.